A database application executing on a host often sends a data-storage system a write request to store certain data at a target location. As part of executing the write request, the data-storage system executes certain data verification steps. Exemplary data verification tests include checksum verification, or checking to see if a particular byte or group of bytes has a particular value. These data verification steps enhance reliability by confirming the integrity of the data record. However, they also increase latency associated with executing the write request. Nevertheless, the integrity of data records is so critical to the operation of a database application that the additional latency imposed by data verification steps is routinely endured.
The particular data verification tests can depend on the target location of each write request. In addition, the particular data verification tests can vary with each database application. For example, the ORACLE™ database application requires that the second byte of a record be “2” and that the fourth through seventh bytes be non-zero. Other database applications may have different requirements for confirming the integrity of data records.
In many cases, the data-storage system also requests that ancillary data be stored by the data-storage system. This ancillary data might include, for example, temporary data created in connection with certain database operations. There is no critical need to verify the integrity of the ancillary data, as there is in the case of actual data records.